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  <meta charset="UTF-8">
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  <title>Document</title>
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<body>
  <script>
    let arr = [
      { a: 10, b: 'aaa', c: 'mmm' },
      { a: 10, b: 'aaa', c: 'mmm' },
      { a: 10, b: 'aaa', c: 'mmm' },
      { a: 10, b: 'aaa', c: 'mmm' },
      { a: 10, b: 'aaa', c: 'mmm' },
      { a: 10, b: 'aaa', c: 'mmm' },
      { a: 10, b: 'aaa', c: 'mmm' },
    ]
    // 求成员中a属性的和
    let res = arr.reduce((pre, next) => {
      return pre + next.a
    }, 0)
    console.log(res);
  </script>

</body>

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